From 26ea670d9723ae116fc273a01a0eca38c41c7581 Mon Sep 17 00:00:00 2001
From: Steven Perron <stevenperron@google.com>
Date: Thu, 19 Sep 2024 15:10:56 -0400
Subject: [PATCH] Fix mismatched memory allocation and deallocation. (#6923)

In NestedNameSpecifier.cpp, the Append function allocates data using
`new`:


https://github.com/microsoft/DirectXShaderCompiler/blob/e1bb926f63ba44119577c845e9d7a1a10c0f50e9/tools/clang/lib/AST/NestedNameSpecifier.cpp#L449-L450

However, if it deallocated using `free`:


https://github.com/microsoft/DirectXShaderCompiler/blob/e1bb926f63ba44119577c845e9d7a1a10c0f50e9/tools/clang/lib/AST/NestedNameSpecifier.cpp#L514-L516

This can cause problems. I'm changing the `free` to `delete`.
---
 tools/clang/lib/AST/NestedNameSpecifier.cpp     |  4 ++--
 .../test/SemaHLSL/nestednamespecifier.hlsl      | 17 +++++++++++++++++
 2 files changed, 19 insertions(+), 2 deletions(-)
 create mode 100644 tools/clang/test/SemaHLSL/nestednamespecifier.hlsl

diff --git a/tools/clang/lib/AST/NestedNameSpecifier.cpp b/tools/clang/lib/AST/NestedNameSpecifier.cpp
index d449018cb..492dd6bc0 100644
--- a/tools/clang/lib/AST/NestedNameSpecifier.cpp
+++ b/tools/clang/lib/AST/NestedNameSpecifier.cpp
@@ -512,7 +512,7 @@ operator=(const NestedNameSpecifierLocBuilder &Other) {
   
   // Free our storage, if we have any.
   if (BufferCapacity) {
-    free(Buffer);
+    delete[] Buffer; // HLSL Change: Use overridable operator delete
     BufferCapacity = 0;
   }
   
@@ -647,7 +647,7 @@ void NestedNameSpecifierLocBuilder::MakeTrivial(ASTContext &Context,
 
 void NestedNameSpecifierLocBuilder::Adopt(NestedNameSpecifierLoc Other) {
   if (BufferCapacity)
-    free(Buffer);
+    delete[] Buffer; // HLSL Change: Use overridable operator delete
 
   if (!Other) {
     Representation = nullptr;
diff --git a/tools/clang/test/SemaHLSL/nestednamespecifier.hlsl b/tools/clang/test/SemaHLSL/nestednamespecifier.hlsl
new file mode 100644
index 000000000..f6d539e59
--- /dev/null
+++ b/tools/clang/test/SemaHLSL/nestednamespecifier.hlsl
@@ -0,0 +1,17 @@
+// RUN: %dxc -T cs_6_0 -E main -HV 2021 -verify %s
+
+// expected-no-diagnostics
+
+template <typename T>
+class C {
+  C cast();
+};
+
+template <class T>
+C<T>
+C<T>::cast() {
+  C result;
+  return result;
+}
+
+[numthreads(64, 1, 1)] void main() {}